There are numerous questions on defense, but the Eagles' season is also largely dependent on Jeremy Maclin's health and adjustments made by Nick Foles. (AP)

The NFL regular season is here. The Eagles have made their final cuts, finalized their practice squad and will reconvene Tuesday at the NovaCare Complex to start practice for the season opener.

On Sunday, the Eagles open their season at the Linc against the Jaguars. Here are five major questions they face going into the 2014 season:

1. Is Nick Foles for real?Nothing we’ve seen from Foles this preseason suggests that he won’t carry over his success from last year into this one. He’s sharper, more in command of the offense and seems to be getting the ball out quicker. But we still really don’t know Nick Foles. Sixteen career starts isn’t a large sample size for a quarterback. And while it’s doubtful he’ll follow in the footsteps of Derek Anderson, it’s also not realistic to pencil in Foles for another 27-touchdown, two-pick, 119.2-quarterback rating season, capped by a Pro Bowl MVP. If he can do that again, all questions and more will be answered. But it’s almost unfair to expect a repeat of those numbers. Opponents have had all offseason to study Foles’ tendencies and shortcomings and they’ve got enough tape on him now to make adjustments. We’ll find out this season if Foles is the real deal and deserves the $100 million contract or if Chip Kelly will be looking for his next franchise quarterback in the offseason. Say what you want about the defense, but the Super Bowl fate of this team rests in the hands of Foles.

2. Will the defense be improved?Without going crazy in free agency, the Eagles tried to shore up their biggest weakness with smart, practical additions. Malcolm Jenkins and Nolan Carroll are expected to help the secondary, and the defensive line has more athleticism this year than last year. The dime package they’ve tinkered with involving Carroll is expected to shore up coverage problems against tight end-dominant offenses. But the key will be hitting quarterbacks. Right now, first-round pick Marcus Smith doesn’t look ready to come in and immediately impact the pass rush. The team’s two best pass rushers, Vinny Curry and Brandon Graham, are still coming off the bench. Despite their attempts to shore up coverage, the defense won’t be any better if opposing quarterbacks aren’t getting rattled.

3. Can Jeremy Maclin stay healthy?We know, Jeremy. You played the most snaps for an Eagles wideout for four straight years. We know, Jeremy. An ACL is a fluke injury that anyone can suffer. (You just happened to do it twice.) Bottom line, Jeremy, you have this tendency of coming out of games with bumps and bruises. Even when you don’t get hurt, like at the end of minicamps and against the Steelers in the preseason, it still looks like you’re about to be carted straight to the ICU.

If he stays healthy, you can pencil Maclin in for a big, big season. Probably somewhere in the 1,100-yard range. He’s that good and this offense is that conducive to his skill set. But the Eagles aren’t overly deep at wideout, so until Maclin shows he can get through a few games without retreating to the sidelines, his health will always be a concern.

4. What if the season comes down to Cody Parkey?Sure, the kid can make big kicks in the preseason. How about when the games really matter? How about when the wind, driving rain and snow factor into the game? How about on the road Monday night on national television against the Colts in Week 2? We have absolutely zero clue if Parkey is up to the challenge of being a starting kicker for an NFL team that’s thinking Super Bowl. And the scary thing is, the coaches don’t know either. The hunch here is that they give Parkey a few weeks to prove himself before they resort to signing a veteran kicker off the scrap heap. Either way, it’s not an ideal situation. Then again, going into the season with Alex Henery wasn’t an ideal one either.

5. Can the offensive line stay healthy again?Last year, all five starting offensive linemen started all 17 games. The only one who dealt with any kind of injury was Jason Peters, but he pushed through and still made All-Pro. These things just don’t happen two straight years. Already, the Eagles are without right tackle Lane Johnson for the first four games as he serves a PED suspension. That puts Allen Barbre in his spot and Barbre didn’t exactly shine in the preseason. Peters, Evan Mathis and Todd Herremans are each over 30. It’s essential that they all stay healthy for this offense to be successful, because this could be the NFL’s best line. But it’s also telling that the Eagles kept four backup linemen again.